Koga-city in Shiga-pre is famous as homeland of Ninja. There are two Ninja homelands in Japan, Iga and Koga, are neighboring, only 30km distance. The Koga Ninja house is in its original location since it was built in 1703.  On the other hand Iga Ninja House was moved to current location.

Koga-ryu Ninja Yashiki (House). This is built in 1703, is the former residence of Mochizuki family. Outside of the house is just normal one-storey Japanese architectual mansion, but in fact has three floors and various traps and tricks are inside of the house, is used to protect from enemy’s attack.